The Force of Muscle Contraction is Most Related to The

Question

The force of muscle contraction is most related to the
A) amount of calcium that is stored within the sarcoplasmic reticulum.
B) amount of neurotransmitter released from the prejunctional vesicles.
C) numbers of cross-bridges formed between actin and myosin.
D) size of the somatic motor neuron.

Accepted Answer

The force of muscle contraction is primarily determined by the number of cross-bridges formed between actin and myosin. When a muscle contracts, myosin heads form cross-bridges with actin filaments, pulling them closer together and causing the muscle to shorten. The more cross-bridges that form, the greater the force of contraction. Therefore, the amount of calcium stored within the sarcoplasmic reticulum, the amount of neurotransmitter released, and the size of the somatic motor neuron may all indirectly affect muscle contraction, but the number of cross-bridges is the most direct determinant of force.